Did Predictions of the Maximum Sunspot Number for Solar Cycle 23 Come True?

Abstract

For solar cycle 23, the maximum sunspot number was predicted by several workers, and the range was very wide, ∼80–210. Cycle 23 started in 1996 and seems to have peaked in 2000, with a smoothed sunspot number maximum of ∼122. From about 20 predictions, 8 were within 122±20. There is an indication that a long-term oscillation of ∼80–100 years may be operative and might have peaked near cycle 20 (1970), and sunspot maxima in cycles in the near future may be smaller and smaller for the next 50 years or so and rebound thereafter in the next 50 years or so.